Curcumin (C.sub.21 H.sub.20 O.sub.6) has many industrial uses. Curcumin is obtained from plants mainly Curcuma. Curcumin, a major constituent of rhizomes of Curcuma species, is present in the form of two related compounds viz. demethoxycurcumin and bisdemethoxycurcumin (together known as curcuminoids). Curcuminoids are used extensively as a food-colouring agent, natural antioxidant, spice, and condiment and for medicinal purposes. It has shown potent anticancer activity [Kuttan, Ramadasan; et. al., Cancer Lett. (Shannon I rel.) 1985, 29(2), 197-202]. Curcuminoids also has potential as an antiviral agent. It has been proven as a modest inhibitor of HIV-1 and HIV-2 proteases [Sui, Z; et. al,. Biorg. Med. Chem. 1993, 6, 415-422].